JP2012220317A - Detector, electronic device, and robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detector capable of accurately detecting a slide direction of external pressure applied to a measurement surface in a wide pressure range.SOLUTION: The detector 1 of the present invention comprises: a first substrate 10 on which a plurality of pressure sensors 12 are arranged around a base point P; and a second substrate 20 formed with an elastic body projection 22 that is elastically deformed with a tip part abutting on the plurality of pressure sensors 12 due to external pressure. The elastic body projection 22 is constituted so as to gradually harden from a side close to the first substrate 10 to a side far therefrom.

Description

  The present invention relates to a detection device, an electronic device, and a robot.

  As a detection device that detects an in-plane direction force (sliding force) of an external pressure applied to the measurement surface (hereinafter simply referred to as “external pressure”), a detection device described in Patent Document 1 is known. The detection device of Patent Document 1 includes a contact that can be displaced on the surface, and detects the direction of the sliding force (slip direction) by detecting the displacement of the contact using a pressure-sensitive element. The bottom surface of the contact is a flat surface, and the contact is in contact with the pressure sensitive element over the entire bottom surface. When a sliding force is applied to the contact, the contact is tilted along the sliding direction of the sliding force, and the pressure distribution in the measurement surface detected by the pressure sensitive element changes. By calculating this pressure distribution, the sliding direction of the external pressure is detected.

JP 2008-164557 A

  In the detection apparatus of Patent Document 1, the contact portion is elastically deformed in a state where the bottom surface of the contact is pressed against the pressure sensitive element, and pressure distribution is generated in the measurement surface by the amount of deformation. Therefore, in order to increase the detection accuracy of the external pressure, the contact is preferably made of a soft material. However, when the contact is made of a soft material, the contact is largely crushed by a small external pressure, and the pressure distribution hardly changes even when a large external pressure is applied. That is, the sensitivity is deteriorated with respect to a large external pressure. On the other hand, in order to provide a detection device that is sensitive to a large external pressure, it is desirable that the contact is made of a hard material. However, in this case, the contact is unlikely to be deformed by a small external pressure. The sensitivity becomes worse.

  An object of the present invention is to provide a detection device, an electronic device, and a robot capable of accurately detecting the sliding direction of an external pressure applied to a measurement surface in a wide pressure range.

  In the detection device of the present invention, a first substrate on which a plurality of pressure sensors are arranged around a reference point, and an elastic protrusion that is elastically deformed in a state in which a tip portion is in contact with the plurality of pressure sensors by external pressure are formed. A second substrate, and the elastic protrusion is configured such that its hardness increases toward a side farther from a side closer to the first substrate.

  According to this configuration, when an external pressure is applied to the elastic protrusion, the soft portion of the elastic protrusion is first crushed to generate a pressure distribution in the surface of the first substrate. When the external pressure is increased, not only the soft part of the elastic projection but also the hard part is elastically deformed. Therefore, even if the soft portion of the elastic protrusion is largely crushed and the soft portion is no longer deformed, the hard portion of the elastic protrusion is elastically deformed, and a large pressure distribution can be generated in the plane of the first substrate. . As described above, in the elastic protrusion, the soft part and the hard part complement each other with a weak detection sensitivity, and as a result, it is possible to detect the external pressure with high sensitivity in a wide pressure range.

  The elastic protrusion is formed by laminating a plurality of layers, and the average hardness of each of the plurality of layers is configured to become harder from a side closer to the first substrate toward a side farther from the first substrate. The hardness of the elastic protrusions may change discontinuously at the boundary between the plurality of layers.

  According to this configuration, since the elastic protrusion is formed of a plurality of layers, the hardness distribution of the elastic protrusion can be accurately controlled by adjusting the hardness of the plurality of layers for each layer. . Since the hardness distribution affects the sensitivity of the detection device, the accuracy of detecting the external pressure is improved by controlling the hardness distribution with high accuracy.

  Each of the plurality of layers may be configured such that the hardness does not change from a side closer to the first substrate to a side farther from the first substrate.

  According to this configuration, since it is only necessary to simply stack a plurality of layers having different hardnesses, the manufacturing is easy.

  Each of the plurality of layers may be configured such that the hardness continuously changes from a side closer to the first substrate toward a side farther from the first substrate.

  According to this configuration, it is possible to smoothly change the detection value (pressure value) of the detection device with respect to a change in external pressure. Therefore, it is possible to accurately detect the sliding direction of the external pressure in a wide pressure range.

  The elastic protrusion may be configured such that the hardness continuously changes from a side closer to the first substrate toward a side farther from the first substrate.

  According to this configuration, it is possible to smoothly change the detection value (pressure value) of the detection device with respect to a change in external pressure. Therefore, it is possible to accurately detect the sliding direction of the external pressure in a wide pressure range.

  The elastic protrusion may have a shape such that a cross section cut by a plane orthogonal to the normal line of the second substrate gradually decreases from the second substrate side toward the first substrate side.

  According to this configuration, load dispersion on the contact surface between the elastic protrusion and the pressure sensor is suppressed, and the detection sensitivity of the external pressure is improved.

  The plurality of pressure sensors may be arranged at point-symmetrical positions around the reference point.

  According to this configuration, since the distance between the reference point and each pressure sensor becomes equal to each other, the relationship between the amount of elastic deformation of the elastic protrusion and the detection value of each pressure sensor becomes equal to each other. For example, when a plurality of pressure sensors are arranged at different distances from the reference point, even if the elastic deformation amounts of the elastic protrusions are the same, the detection values of the pressure sensors are different from each other. For this reason, when calculating the difference between the detection values, a correction coefficient corresponding to the arrangement position of each pressure sensor is required. However, according to the detection apparatus of the present invention, the relationship between the amount of elastic deformation of the elastic protrusion and the detection value of each pressure sensor becomes equal to each other, so that the correction coefficient is not necessary. Therefore, it becomes easy to calculate the sliding direction of the external pressure from the detection value of each pressure sensor.

  The plurality of pressure sensors may be arranged in a matrix in two directions orthogonal to each other.

  According to this configuration, the sliding direction of the external pressure can be calculated as a vector in two directions orthogonal to each other by obtaining a difference between detection values of pressure sensors adjacent to each other.

  A plurality of the elastic protrusions may be formed on the second substrate, and the plurality of elastic protrusions may be spaced apart from each other.

  According to this configuration, since the interference between the elastic protrusions is suppressed, it is possible to accurately detect the external pressure in the entire region where the plurality of elastic protrusions are installed.

  The elastic protrusion is elastically deformed by the external pressure to calculate the difference between the pressure values detected by the pressure sensors arbitrarily combined among the pressure values detected by the plurality of pressure sensors, and based on the difference And a calculation device for calculating the sliding direction and magnitude of the external pressure.

  The electronic apparatus or robot of the present invention includes the detection device of the present invention.

  According to this configuration, it is possible to provide an electronic device or a robot that can detect the sliding direction of the external pressure with high accuracy.

It is a disassembled perspective view which shows schematic structure of the detection apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the change of the pressure value by the pressure sensor which concerns on 1st Embodiment. It is a top view which shows the change of the pressure value by the pressure sensor which concerns on 1st Embodiment. It is a figure which shows the output characteristic of the detection apparatus which concerns on 1st Embodiment. It is a figure which shows the coordinate system of the sensing area | region which concerns on 1st Embodiment. It is a figure which shows the pressure distribution of the perpendicular direction by the pressure sensor which concerns on 1st Embodiment. It is a figure which shows the example of calculation of the slip direction by the pressure sensor which concerns on 1st Embodiment. It is sectional drawing which shows the manufacturing method of the elastic body protrusion which concerns on 1st Embodiment. It is sectional drawing which shows schematic structure of the detection apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows the output characteristic of the detection apparatus which concerns on 2nd Embodiment. It is sectional drawing which shows the manufacturing method of the elastic body protrusion which concerns on 2nd Embodiment. It is sectional drawing which shows schematic structure of the detection apparatus which concerns on 3rd Embodiment of this invention. It is a figure which shows the output characteristic of the detection apparatus which concerns on 3rd Embodiment. It is a schematic diagram which shows schematic structure of the mobile telephone which is an example of an electronic device. It is a schematic diagram which shows schematic structure of the portable information terminal which is an example of an electronic device. It is a schematic diagram which shows an example of a robot.

  Embodiments of the present invention will be described below with reference to the drawings. This embodiment shows one aspect of the present invention, and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, an actual structure and a scale, a number, and the like in each structure are different.

  In the following description, the XYZ rectangular coordinate system shown in FIG. 1 is set, and each member will be described with reference to this XYZ rectangular coordinate system. In the XYZ orthogonal coordinate system, the X axis and the Y axis are set in a direction parallel to the first substrate 10, and the Z axis is set in a direction orthogonal to the first substrate 10.

(First embodiment)
FIG. 1 is an exploded perspective view showing a schematic configuration of a detection apparatus 1 according to the first embodiment of the present invention. In FIG. 1, reference symbol P denotes a reference point, and reference symbol S denotes a unit detection region detected by a plurality of pressure sensors 12 arranged corresponding to one elastic protrusion 22. Reference numerals S 1, S 2, S 3 and S 4 indicate detection areas detected by one pressure sensor 12.

  The detection device 1 is a pressure sensor type touch pad that detects the direction and magnitude of an external pressure applied to a reference point, and is used as a pointing device instead of a mouse in an electronic device such as a notebook computer. The “reference point” is a point where the center of the elastic protrusion is positioned, that is, the center point of the unit detection region. Further, the pressure sensor method is not particularly limited, and for example, a capacitance method, a photo sensor method, or the like can be used.

  As shown in FIG. 1, the detection device 1 is elastic in a state in which a first substrate 10 having a plurality of pressure sensors 12 arranged around a reference point P and a front end portion abuts on the first substrate 10 by external pressure. And a second substrate 20 on which a deformable elastic protrusion 22 is formed.

  The detection device 1 calculates the difference between the pressure values detected by the pressure sensors 12 that are arbitrarily combined among the pressure values detected by the plurality of pressure sensors 12 as the elastic protrusions 22 are elastically deformed by the external pressure. And an arithmetic unit 30 that calculates the direction and magnitude of the external pressure applied based on the difference.

  The first substrate 10 includes a rectangular plate-shaped first substrate body 11 made of a material such as glass, quartz, and plastic, for example, and a plurality of pressure sensors 12 arranged on the first substrate body 11. It is configured. For example, the size (size in plan view) of the first substrate body 11 is about 56 mm long × 56 mm wide.

  The plurality of pressure sensors 12 are arranged point-symmetrically with respect to the reference point P. For example, the plurality of pressure sensors 12 are arranged in a matrix in two directions (X direction and Y direction) orthogonal to each other. Thereby, since the distance between the reference point P and each pressure sensor 12 becomes equal to each other, the relationship between the deformation of the elastic protrusion 22 and the pressure value detected by each pressure sensor 12 becomes equal to each other. Therefore, it becomes easy to calculate the difference between the pressure values detected by the pressure sensors 12 arbitrarily combined among the pressure values of the pressure sensors 12. Further, when the pressure sensors are arranged in a matrix in two directions orthogonal to each other, the sliding direction of the external pressure can be calculated as a vector in two directions orthogonal to each other, so that the calculation becomes easy. A method for calculating the difference between the pressure values will be described later.

  The interval between the adjacent pressure sensors 12 is about 0.1 mm. For this reason, noise is not applied to the pressure value detected by the pressure sensor 12 at the adjacent position due to the influence of disturbance, static electricity, or the like.

  A plurality of pressure sensors 12 are arranged in a total of four rows and two columns per unit detection area S. The center of the four pressure sensors 12 (the center of the unit detection region S) is the reference point P. For example, the size of the unit detection area S (size in plan view) is about 2.8 mm long × 2.8 mm wide. Further, the areas of the four pressure sensors 12 are substantially equal. As the pressure sensor 12, for example, a known pressure sensitive element such as a diaphragm gauge can be used. The pressure sensor 12 converts, for example, a pressure applied to the diaphragm when an external pressure is applied to the contact surface into an electric signal.

  The second substrate 20 includes a rectangular plate-shaped second substrate main body 21 and a plurality of elastic protrusions 22 arranged on the second substrate main body 21. The second substrate body 21 is a part that directly receives external pressure. The second substrate body 21 can be made of a material such as glass, quartz, and plastic, or can be made of a resin material such as a urethane foam resin or a silicone resin.

  The plurality of elastic protrusions 22 are arranged in a matrix in the X direction and the Y direction on the second substrate body 21. The elastic protrusions 22 are configured such that the hardness increases from the side closer to the first substrate 10 (−Z side) to the side farther (+ Z side). In the example of FIG. 1, the elastic protrusion 22 is formed by laminating a plurality of layers (first layer 22a, second layer 22b), and the average hardness of each of the plurality of layers is the first It is comprised so that it may harden toward the side far from the side near 1 board | substrate 10, and the hardness of the elastic body protrusion 22 is changing discontinuously in the boundary part of several layer 22a, 22b. For example, each of the plurality of layers 22a and 22b is configured such that the hardness does not change from the side closer to the first substrate 10 toward the side farther from the first substrate 10, and the average of the first layers 22a arranged at the base end portion The hardness is 50, and the average hardness of the second layer 22b disposed at the tip is 30.

  “Hardness” refers to durometer hardness (type A, measured by a durometer conforming to ISO7619), and “average hardness of a layer” refers to the hardness of the micro area of the layer as a whole. Is a value obtained by dividing the volume by the volume of the layer.

  The elastic protrusion 22 has a shape such that a cross section cut by a plane orthogonal to the normal line of the second substrate gradually decreases from the second substrate 20 side toward the first substrate 10 side. By forming the tip of the elastic protrusion 22 to be tapered, load distribution on the contact surface between the elastic protrusion 22 and the pressure sensor 12 is suppressed, and the detection sensitivity of the external pressure is improved. In the example of FIG. 1, the tip of the elastic protrusion 22 has a spherical weight, but the shape of the elastic protrusion 22 is not limited to this.

  The elastic protrusion 22 is in contact with the first substrate 10 (the plurality of pressure sensors 12 on the first substrate body 11) at the tip. The center of gravity of the elastic protrusion 22 is initially arranged at a position overlapping the reference point P. Further, the plurality of elastic body protrusions 22 are spaced apart from each other. For this reason, it is possible to allow a deformation amount in a direction parallel to the surface of the second substrate body 21 when the elastic protrusion 22 is elastically deformed.

  The size of the elastic protrusion 22 can be arbitrarily set. Here, the diameter of the base of the elastic protrusion 22 (the diameter of the portion where the elastic protrusion 22 contacts the first substrate 10) is about 1.8 mm. The height of the elastic protrusion 22 (the distance in the Z direction of the elastic protrusion 22) is about 2 mm. The spacing between adjacent elastic projections 22 is about 1 mm.

  2 and 3 are explanatory views of a method for detecting the direction and magnitude of the external pressure acting on the reference point P. FIG. 2A to 2C are cross-sectional views showing changes in pressure values by the pressure sensor according to the first embodiment. FIGS. 3A to 3C are plan views showing changes in pressure values by the pressure sensor according to the first embodiment, corresponding to FIGS. 2A to 2C. 2A and 3A show a state before external pressure is applied to the surface of the second substrate 20 (when no external pressure is applied). FIG. 2B and FIG. 3B show a state in which an external pressure in a vertical direction (a state without a sliding force) is applied to the surface of the second substrate 20. FIG. 2C and FIG. 3C show a state where an external pressure in an oblique direction (with a sliding force) is applied to the surface of the second substrate 20. 3A to 3C, the symbol G indicates the center of gravity (pressure center) of the elastic protrusion 22.

  As shown in FIGS. 2A and 3A, the elastic protrusion 22 is not deformed before external pressure is applied to the surface of the second substrate 20. Thereby, the distance between the first substrate 10 and the second substrate 20 is kept constant. At this time, the center of gravity G of the elastic protrusion 22 is arranged at a position overlapping the reference point P. The pressure value of each pressure sensor 12 at this time is stored in a memory (not shown). The direction and magnitude of the external pressure acting are obtained based on the pressure value of each pressure sensor 12 stored in the memory.

  As shown in FIGS. 2B and 3B, when an external pressure in the vertical direction is applied to the surface of the second substrate 20, the elastic protrusion 22 has the tip portion disposed on the surface of the first substrate 10. In addition, it is compressed and deformed in the Z direction in contact with the plurality of pressure sensors 12. As a result, the second substrate 20 bends in the −Z direction, and the distance between the first substrate 10 and the second substrate 20 becomes smaller than when there is no external pressure. The pressure value of the pressure sensor at this time becomes larger than when there is no external pressure. The amount of change is substantially the same for each pressure sensor.

  As shown in FIGS. 2C and 3C, when an external pressure in an oblique direction is applied to the surface of the second substrate 20, the elastic protrusion 22 has the tip portion disposed on the surface of the first substrate 10. In a state where the pressure sensor 12 is in contact with the plurality of pressure sensors 12, the pressure sensor 12 is inclined and compressed and deformed. As a result, the second substrate 20 bends in the −Z direction, and the distance between the first substrate 10 and the second substrate 20 becomes smaller than when there is no external pressure. At this time, the center of gravity G of the elastic protrusion 22 is shifted from the reference point P in the + X direction and the + Y direction. In this case, the overlapping areas of the tip of the elastic protrusion 22 and the four pressure sensors 12 are different from each other. Specifically, the area where the tip of the elastic protrusion 22 and the four pressure sensors 12 overlap is greater than the area overlapping the portions of the four pressure sensors 12 arranged in the −X direction and the −Y direction. And the area which overlaps with the part arrange | positioned at + Y direction becomes larger.

  The elastic protrusion 22 is biased in deformation by an external pressure in an oblique direction. That is, the center of gravity of the elastic protrusion 22 is displaced from the reference point P and moves in the sliding direction (X direction and Y direction). Then, different pressure values are detected by each pressure sensor. Specifically, a relatively large pressure value is detected by the pressure sensor at a position overlapping with the center of gravity of the elastic protrusion 22, and a relatively small pressure value is detected by a pressure sensor at a position not overlapping with the center of gravity of the elastic protrusion 22. Will be. And the direction and magnitude | size to which the external pressure was applied are calculated | required based on the calculation method of the difference mentioned later.

  FIG. 4 is a diagram illustrating output characteristics of the detection device 1. The horizontal axis represents the magnitude of the external pressure applied to the second substrate 20, and the vertical axis represents the pressure value detected by the detection device 1.

  As described above, the elastic protrusion 22 is formed by sequentially laminating a plurality of layers (first layer 22a, second layer 22b) having different hardness from the second substrate body 21 side. Are configured so that the hardness increases toward the side farther from the side closer to the first substrate 10. Therefore, when the magnitude of the external pressure is changed, a plurality of output characteristics a1 and a2 corresponding to the elastic characteristics of the layers 22a and 22b of the elastic protrusion 22 appear, and an output characteristic obtained by combining them is an output characteristic a3 of the detection apparatus 1. It becomes.

  For example, in the low pressure region where the external pressure is small, the second layer 22b of the elastic protrusion 22 is elastically deformed according to the output characteristic a1, and a pressure distribution is generated in the surface of the first substrate 10. Since the second layer 22b is formed of a soft material, it is greatly deformed even by a small external pressure, and a large pressure distribution is generated in the surface of the first substrate 10. On the other hand, in the high pressure region where the external pressure is large, the second layer 22b is completely crushed, and further elastic deformation is less likely to occur. However, since the first layer 22a harder than the second layer 22b is elastically deformed according to the output characteristic a2, a large pressure distribution can be generated in the plane of the first substrate 10.

  When the elastic protrusion 22 is formed of only a soft material or only a hard material, the external pressure cannot be detected with high sensitivity in the high pressure region or the low pressure region. However, if a part of the elastic protrusion 22 is formed of a soft material and a part of the elastic protrusion 22 is formed of a hard material, the soft part and the hard part supplement each other with a weak detection sensitivity. As a result, the external pressure is increased over a wide pressure range. It becomes possible to detect with high sensitivity.

  FIG. 5 is a diagram illustrating a coordinate system of the sensing area according to the first embodiment. FIG. 6 is a view showing a pressure distribution in the vertical direction by the pressure sensor according to the first embodiment. FIG. 7 is a diagram illustrating a calculation example of the slip direction by the pressure sensor according to the first embodiment. In the following description, the pressure sensors included in the detection areas S1, S2, S3, and S4 are simply referred to as pressure sensors S1, S2, S3, and S4.

As shown in FIG. 5, a plurality of pressure sensors S1 to S4 are arranged in a unit of two vertical rows and two horizontal columns per unit detection region S. Here, assuming that the pressure values (detected values) detected by the pressure sensors S1 to S4 are P _S1 , P _S2 , P _S3 , and P _S4 , respectively, the X direction component Fx of the external force (X of the in-plane direction components of the external force) The ratio of the component force acting in the direction) is expressed by the following equation (1).

  Further, the Y direction component Fy of the external force (the ratio of the component force acting in the Y direction among the in-plane direction components of the external force) is expressed by the following equation (2).

  The Z direction component Fz of the external force (vertical direction component of the external force) is expressed by the following formula (3).

  In this embodiment, the elastic protrusions are elastically deformed by external pressure, and the difference between the pressure values detected by the pressure sensors arbitrarily combined among the pressure values detected by the four pressure sensors S1 to S4 is calculated. The direction in which the external pressure is applied is calculated based on the difference.

  As shown in Expression (1), in the X direction component Fx of the external pressure, the values detected by the pressure sensors S2 and S4 arranged in the + X direction among the pressure values detected by the four pressure sensors S1 to S4 are shown. In addition, the values detected by the pressure sensors S1 and S3 arranged in the −X direction are combined. As described above, the X-direction component of the external pressure is based on the difference between the pressure value obtained by the combination of the pressure sensors S2 and S4 arranged in the + X direction and the pressure value obtained by the combination of the pressure sensors S1 and S3 arranged in the -X direction. Desired.

  As shown in the equation (2), in the Y direction component Fy of the external pressure, the values detected by the pressure sensors S1 and S2 arranged in the + Y direction among the pressure values detected by the four pressure sensors S1 to S4 are shown. The values detected by the pressure sensors S3 and S4 arranged in the −Y direction are combined together. Thus, the Y-direction component of the external pressure is based on the difference between the pressure value obtained by combining the pressure sensors S1 and S2 arranged in the + Y direction and the pressure value obtained by combining the pressure sensors S3 and S4 arranged in the -Y direction. Desired.

  As shown in Expression (3), the Z direction component Fz of the external pressure is obtained by a resultant force obtained by adding the pressure values of the four pressure sensors S1 to S4. However, the detected value of the Z direction component Fz of the external pressure tends to be detected larger than the X direction component Fx of the external pressure and the Y direction component Fy (component force) of the external pressure. Therefore, in order to align the detected value of the Z direction component Fz of the external pressure with the detected values of the X direction component Fx of the external pressure and the Y direction component Fy of the external pressure, a correction coefficient determined by the material and shape of the elastic protrusion 22 is used. It is necessary to correct the detection value as appropriate.

  As shown in FIG. 6, consider a case where a position on the upper left side of the center of the detection surface of the touchpad is pushed diagonally with a finger. At this time, the pressure in the vertical direction of the external pressure is the largest at the center of the portion where the external pressure is applied (the output voltage of the pressure sensor is about 90 to 120 mV). Moreover, the pressure in the vertical direction of the external pressure decreases in the order of the peripheral portion (about 60 to 90 mV) and the outermost peripheral portion (about 30 to 60 mV) next to the central portion. Moreover, the output voltage of the pressure sensor is about 0 to 30 mV in the region not pressed by the finger. The touchpad has unit detection areas (area where pressure sensors S1 to S4 are arranged in a total of 4 in 2 rows and 2 columns) arranged in a matrix (for example, a total of 225 in 15 rows x 15 columns). Suppose that

  As shown in FIG. 7, a method for calculating the in-plane direction component (slip direction) of the external pressure when the position on the upper left side of the center of the detection surface of the touchpad is obliquely pressed with a finger will be considered. At this time, it is assumed that the finger pressing force (external force) acts on the portion arranged in the vertical 3 rows × horizontal 3 columns among the vertical rows 15 × horizontal 15 columns. Here, the pressure in the vertical direction of the external pressure is the largest at the central portion of the portion where the external pressure is applied as in FIG. 6 (110 mV).

  Each unit detection area arranged in 3 rows x 3 columns has four pressure sensors S1 to S4, which are arbitrarily combined among the pressure values detected by the pressure sensors S1 to S4. The difference between the pressure values detected by each pressure sensor is calculated, and the direction in which the external pressure is applied is calculated based on the difference. That is, in each unit detection region, the X-direction component Fx of the external pressure and the Y-direction component Fy of the external pressure are calculated based on the above formulas (1) and (2). Here, it can be seen that the external pressure acts in the direction of about 123 ° counterclockwise with respect to the + X direction. In calculating the direction in which the external pressure acts, the calculation is performed by the average value of the nine calculation results or the maximum value (for example, a detection value larger than a predetermined threshold value) of the nine calculation results. The method can be used.

  FIG. 8 is an explanatory view showing an example of a method for manufacturing the elastic protrusion 22.

  When manufacturing the elastic protrusion 22, first, as shown in FIG. 8A, a first mold 40 provided with an opening 40 a corresponding to the second layer 22 b is prepared, and FIG. ), The opening 40a of the first mold 40 is filled with an elastic material such as silicone rubber to form the second layer 22b. The second layer 22b is made of a soft material having a durometer hardness of about 30. As such a material, silicone RTV rubber KE-14 (trade name) manufactured by Shin-Etsu Silicone is suitable.

  Next, as shown in FIG. 8C, a second die 41 provided with an opening 41a corresponding to the first layer 22a is laminated on the first die 40, and FIG. As shown, the first layer 22a is formed by filling the second layer 22b exposed in the opening 41a of the second mold 41 with an elastic material such as silicone rubber. The first layer 22a is formed of a hard material having a durometer hardness of about 50. As such a material, silicone RTV rubber KE-17 (trade name) manufactured by Shin-Etsu Silicone is suitable.

  The elastic protrusions 22 manufactured by the above method are welded or bonded to the second substrate body 21 shown in FIG. 1 and integrated with the second substrate body 21. And the 1st type | mold 40 and the 2nd type | mold 41 are removed from the elastic protrusion 22, and the 2nd board | substrate 20 is completed.

  In this method, the openings of the first mold 40 and the second mold 41 are sequentially filled with an elastic material, so the hardness of the first layer 22a and the second layer 22b does not change in the thickness direction. Therefore, the hardness of the elastic protrusion 22 is discontinuous at the boundary between the first layer 22a and the second layer 22b, and the output characteristic of the detection device is a portion that changes discontinuously from the low pressure side to the high pressure side. (Portion indicated by reference A in FIG. 4) occurs. However, in the above method, since it is only necessary to simply stack a plurality of layers having different hardnesses, manufacturing is easy and cost can be reduced.

  According to the detection device 1 of the present embodiment, since the hardness of the elastic protrusion 22 is formed so as to become harder from the side closer to the first substrate 10 to the side farther from the first substrate 10, the external pressure is reduced from the low pressure region where the external pressure is small. It is possible to detect the external pressure with high sensitivity in a wide pressure range up to a high pressure region. Further, since the elastic protrusion 22 is formed by laminating a plurality of layers 22a and 22b having different hardnesses, the elastic protrusion 22 can be adjusted by adjusting the hardness of each of the layers 22a and 22b for each layer. The hardness distribution can be controlled with high accuracy. Since the hardness distribution affects the sensitivity of the detection apparatus 1, the accuracy of detecting the external pressure is improved by controlling the hardness distribution with high accuracy.

  In the present embodiment, the elastic protrusions 22 are formed of two layers, but the elastic protrusions 22 may be formed of three or more layers. As the number of layers increases, a portion that changes discontinuously in the output characteristics of the detection device 1 (portion indicated by symbol A in FIG. 4) is less likely to occur. Value) can be changed smoothly. Therefore, it is possible to accurately detect the sliding direction of the external pressure in a wide pressure range.

(Second Embodiment)
FIG. 9 is a cross-sectional view illustrating a schematic configuration of the detection device 2 according to the second embodiment. Constituent elements common to the detection apparatus 1 of the first embodiment in the detection apparatus 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The difference between the detection device 2 and the detection device 1 of the first embodiment is that the hardness of the elastic protrusions 23 is such that the hardness of the elastic protrusions 23 increases from the side closer to the first substrate 10 toward the far side. Is a point that changes continuously. The hardness of the elastic protrusion 23 is controlled, for example, by changing the degree of curing when the elastic protrusion 23 is cured in the thickness direction (Z direction) of the elastic protrusion 23. The second substrate 24 is formed by welding or bonding the elastic protrusions 23 to the second substrate body 21.

  FIG. 10 is a diagram illustrating output characteristics of the detection device 2. The horizontal axis represents the magnitude of the external pressure applied to the second substrate 24, and the vertical axis represents the pressure value detected by the detection device 2.

  As described above, the hardness of the elastic protrusion 23 continuously changes from the side closer to the first substrate 10 toward the side farther from the side. The elastic protrusion 23 has the same configuration as that in which a number of layers having different hardnesses are sequentially stacked from the second substrate body 21 side. Therefore, a large number of output characteristics b1, b2, b3, b4,... Corresponding to the elastic characteristics of each layer of the elastic protrusion 23 appear, and an output characteristic obtained by combining them becomes the output characteristic b5 of the detection device 2.

  For example, in the low pressure region where the external pressure is small, the softest part of the elastic protrusion 23 is elastically deformed according to the output characteristic b 1, and a pressure distribution is generated in the surface of the first substrate 10. When the external pressure is increased, the soft portion is not elastically deformed any more, but the harder portion is sequentially elastically deformed according to the output characteristics b2, b3, b4. A distribution can be produced. As a result, it is possible to detect the external pressure with high sensitivity in a wide pressure range.

  FIG. 11 is an explanatory view showing an example of a method for manufacturing the elastic protrusion 23.

  When manufacturing the elastic protrusion 23, first, as shown in FIG. 11A, a mold 42 having an opening 42a corresponding to the elastic protrusion 23 is prepared, and the bottom of the opening 42a of the mold 42 is prepared. A curing inhibitor 43 is disposed. The curing inhibitor 43 is a substance containing sulfur, phosphorus, nitrogen compound, water, organometallic salt, and the like, and examples thereof include waxes such as pine sprout.

  Next, as shown in FIG. 11B, the opening 42a of the mold 42 is filled with an elastic material 44 such as silicone rubber. Then, as shown in FIG. 11 (c), the elastic material 44 is cured to form the elastic protrusions 23. As the elastic material 44, for example, an addition reaction type silicone RTV rubber KE-17 (trade name) manufactured by Shin-Etsu Silicone Co., Ltd. is used.

  When an addition reaction type RTV rubber is used as the elastic material 44, the curing inhibitor 43 inhibits the curing of the elastic material 44 in a portion close to the curing inhibitor, resulting in poor curing. A portion of the elastic material 44 far from the curing inhibitor 43 does not have poor curing because the influence of the curing inhibitor 43 is reduced. As a result, the tip of the elastic protrusion 23 has a large elasticity (soft), and the base end of the elastic protrusion 23 has a small elasticity (hard).

  The elastic protrusions 23 manufactured by the above method are welded or bonded to the second substrate body 21 shown in FIG. 9 and integrated with the second substrate body 21. And the type | mold 42 is removed from the elastic body protrusion 23, and the 2nd board | substrate 24 is completed.

  In the detection device 2 of the present embodiment, the hardness of the elastic protrusion 23 continuously changes from the side closer to the curing inhibitor 43 to the side farther. Since the region in which the hardness changes discontinuously (for example, the portion indicated by the symbol A in FIG. 4) is not formed inside the elastic protrusion 23, the detection value of the detection device 2 (with respect to the change in external pressure ( Pressure value) can be changed smoothly. Therefore, it is possible to accurately detect the sliding direction of the external pressure in a wide pressure range.

(Third embodiment)
FIG. 12 is a cross-sectional view illustrating a schematic configuration of the detection device 3 according to the third embodiment. Constituent elements common to the detection apparatus 1 of the first embodiment in the detection apparatus 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The detection device 3 is different from the detection device 1 of the first embodiment in that the elastic protrusion 27 is formed by laminating a plurality of layers (first layer 25, second layer 26). , 26 is configured such that the hardness continuously changes from the side closer to the first substrate 10 toward the side farther from the first substrate 10. The hardness of each layer 25, 26 is controlled, for example, by changing the degree of curing when curing each layer 25, 26 in the layer thickness direction (Z direction). The average hardness of each of the plurality of layers 25 and 26 is configured to become harder from the side closer to the first substrate 10 toward the side farther from the first substrate 10 (average hardness of the first layer 25> second layer. 26, the hardness of the elastic protrusion 27 changes discontinuously at the boundary between the plurality of layers 25 and 26.

  The first layer 25 and the second layer 26 can be manufactured by a method similar to that shown in FIG. In FIG. 8, the first layer and the second layer are uniformly cured in the entire layer thickness direction, but in the present embodiment, the first layer 25 and the second layer 26 have a hardness distribution in the thickness direction. For this purpose, a curing inhibitor as shown in FIG. 11 is used to make the degree of curing of the first layer 25 and the second layer 26 non-uniform in the thickness direction. By doing so, the portion of the second layer 26 on the first layer 25 side is hardened so that a large change in hardness does not occur at the boundary between the second layer 26 and the first layer 25.

  FIG. 13 is a diagram illustrating output characteristics of the detection device 3. The horizontal axis represents the magnitude of the external pressure applied to the second substrate 28, and the vertical axis represents the pressure value detected by the detection device 3.

  As described above, the hardness of each of the first layer 25 and the second layer 26 continuously changes from the side closer to the first substrate 10 toward the side farther from the first substrate 10. The first layer 25 has a configuration equivalent to that a plurality of layers having different hardnesses are sequentially laminated from the second substrate body 21 side, and the second layer 26 has a plurality of layers having different hardnesses that are stacked on the second substrate body 21. It becomes the structure equivalent to what laminated | stacked sequentially from the side. Therefore, in the low pressure region where the external pressure is small, a large number of output characteristics appear according to the elastic characteristics of the respective layers constituting the second layer 26, and an output characteristic c <b> 1 obtained by combining them becomes the output characteristic of the low pressure region of the detection device 3. In the high pressure region where the external pressure is large, a large number of output characteristics appear according to the elastic properties of the layers constituting the first layer 25, and an output property c <b> 2 obtained by combining them becomes the output property of the high pressure region of the detection device 3. A combination of the output characteristic c1 in the low pressure region and the output characteristic c2 in the high pressure region is the output characteristic c3 of the detection device 3.

  Since the first layer 25 and the second layer 26 are provided with hardness distributions such that the hardness increases from the side closer to the first substrate 10 toward the side farther from the first substrate 10, the first layer 25, the second layer 26, The change in hardness at the boundary is small. For this reason, the output characteristic c1 in the low pressure region and the output characteristic c2 in the high pressure region are smoothly connected, and the output characteristic c3 as a whole is also smooth. Therefore, a large discontinuity as shown by the symbol A in FIG. 4 hardly occurs at the boundary between the low pressure region and the high pressure region, and as a result, it is possible to detect the external pressure with high sensitivity in a wide pressure range. .

(Electronics)
FIG. 14 is a schematic diagram showing a schematic configuration of a mobile phone 1000 to which the detection device according to the embodiment is applied. The cellular phone 1000 includes a plurality of operation buttons 1003, scroll buttons 1002, and a liquid crystal panel 1001 as a display unit. The liquid crystal panel 1001 incorporates the detection device according to the above embodiment. By operating the scroll button 1002, the screen displayed on the liquid crystal panel 1001 is scrolled. A menu button (not shown) is displayed on the liquid crystal panel 1001. For example, when a menu button is touched with a finger, a phone book is displayed or a phone number of a mobile phone is displayed.

  FIG. 15 is a schematic diagram showing a schematic configuration of a personal digital assistant (PDA) 2000 to which the detection apparatus according to the embodiment is applied. The portable information terminal 2000 includes a plurality of operation buttons 2002, a power switch 2003, and a liquid crystal panel 2001 as a display unit. The liquid crystal panel 2001 incorporates the detection device according to the above embodiment. When the power switch 2003 is operated, a menu button is displayed on the liquid crystal panel 2001. For example, when a menu button (not shown) is touched with a finger, an address book is displayed or a schedule book is displayed.

  According to such an electronic device, since the above-described detection device is provided, an electronic device capable of detecting the direction and magnitude of the external pressure with high accuracy can be provided.

  Other electronic devices include, for example, personal computers, video camera monitors, car navigation devices, pagers, electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, digital still cameras, and touch panels. Equipment and the like. The detection apparatus according to the present invention can also be applied to these electronic devices.

(robot)
FIG. 16 is a schematic diagram illustrating a schematic configuration of a robot 3000 to which the detection device according to the embodiment is applied. As shown in FIG. 16A, the robot 3000 has a robot hand including a main body 3003, a pair of arms 3002, and a grip 3001 to which the detection device is applied. For example, when a drive signal is transmitted to the arm unit 3002 by a control device such as a remote controller, the pair of arm units 3002 open and close.

  As shown in FIG. 16B, consider a case where the robot 3000 holds an object 3010 such as a cup. At this time, the force acting on the object 3010 is detected as a pressure by the grip portion 3001. Since the robot 3000 includes the above-described detection device as the gripping unit 3001, a force in a direction sliding with gravity Mg (slip force component) is combined with a force in a direction perpendicular to the surface (contact surface) of the object 3010. It is possible to detect. For example, it can be held while adjusting the force according to the texture of the object 3010 so as not to deform a soft object or drop a slippery object.

  According to the robot 3000, since the above-described detection device is provided, it is possible to provide a robot that can detect the direction and magnitude of the external pressure with high accuracy.

DESCRIPTION OF SYMBOLS 1, 2, 3 ... Detection apparatus, 10 ... 1st board | substrate, 12 ... Pressure sensor, 20 ... 2nd board | substrate, 22 ... Elastic body protrusion, 22a ... 1st layer, 22b ... 2nd layer, 23 ... Elastic body protrusion, 24 ... 2nd board | substrate, 25 ... 1st layer, 26 ... 2nd layer, 27 ... Elastic body protrusion, 28 ... 2nd board | substrate, 30 ... Arithmetic unit, 1000 ... Mobile phone, 2000 ... Portable information terminal, 3000 ... Robot, P ... Reference point

Claims (12)

A first substrate on which a plurality of pressure sensors are arranged around a reference point;
A second substrate on which an elastic protrusion is formed that is elastically deformed in a state in which a tip portion is in contact with the plurality of pressure sensors by external pressure,
The detection device is configured such that the elastic protrusions become harder from a side closer to the first substrate toward a side farther from the first substrate.   The elastic protrusion is formed by laminating a plurality of layers, and the average hardness of each of the plurality of layers is configured to become harder from a side closer to the first substrate toward a side farther from the first substrate. The detection device according to claim 1, wherein the hardness of the elastic protrusion changes discontinuously at a boundary portion of the plurality of layers.   The detection device according to claim 2, wherein each of the plurality of layers is configured so that the hardness does not change from a side closer to the first substrate to a side farther from the first substrate.   3. The detection device according to claim 2, wherein each of the plurality of layers is configured so that the hardness continuously changes from a side closer to the first substrate toward a side farther from the first substrate.   The detection device according to claim 1, wherein the elastic protrusion is configured so that the hardness continuously changes from a side closer to the first substrate toward a side farther from the first substrate.   2. The elastic protrusion has a shape such that a cross section cut by a plane orthogonal to a normal line of the second substrate gradually decreases from the second substrate side toward the first substrate side. The detection apparatus of any one of -5.   The detection device according to claim 1, wherein the plurality of pressure sensors are arranged at point-symmetrical positions around the reference point.   The detection device according to claim 7, wherein the plurality of pressure sensors are arranged in a matrix in two directions orthogonal to each other. A plurality of the elastic protrusions are formed on the second substrate,
The detection device according to claim 1, wherein the plurality of elastic body protrusions are spaced apart from each other.   The elastic protrusion is elastically deformed by the external pressure to calculate the difference between the pressure values detected by the pressure sensors arbitrarily combined among the pressure values detected by the plurality of pressure sensors, and based on the difference The detection device according to claim 1, further comprising an arithmetic device that calculates a slip direction and a magnitude of the external pressure.   The electronic device provided with the detection apparatus of any one of Claims 1-10.   The robot provided with the detection apparatus of any one of Claims 1-10.

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